DB2® Everyplace (DB2e) is a small-footprint and self-managing database product that extends enterprise applications and data to mobile devices. WebSphere® Everyplace Access provides mobile application features, such as synchronization, intelligent notification, transcoding, and mobile messaging. For more information on DB2, see DB2 Developer Domain. For more information on WebSphere Everyplace, see Wireless with WebSphere Zone.

Question: I come from a J2ME background and am working on my first WebSphere Everyplace Access project. I would like to know how J2ME is catered for J2ME limitations addressed by technologies like DB2e. (submitted by LN)

Answer: For the database: While there is no SQL "database" supported in DB2e MIDP due to 50k application size limitations, the SQL meta information (colname, coltype, isnullable, isprimarykey) is stored per table, and the table data is indexed and packed into the Record Management Store. The TableMetaData class provides access to this information by the application.

For the Record Management Store: The Record Store is extremely slow on writes after 3 records (2-5 seconds each). FastRecordStore packs 10 rows into each RMS record, dramatically reducing write times. The index class wraps FastRecordStore for fast access by primary keys to rows for delete and update operations to avoid scanning the complete RMS tables. FastRecordStore persists if the store is "dirty" for faster synchronization times (changes to the server).

For slow wireless network speed: This uses less chatty protocol for MIDP, which makes 1/5 less connections (each connection can take up to 10 seconds). One request is made and 2400 bytes (for Nextel network, configurable) messages are received. If more than one message is required, then another short request is made for the next packet until all packets are received.

Question: Is there any plans by IBM to support offline mode and synchronization for regular Web browser applications with WebSphere Everyplace. Just like it was implemented in Oracle® Lite 9i. (submitted by Dmitriy Kirillin)

Answer: You can develop JSP applications accessing DB2e database for Windows® and PocketPC since the last release in DB2e V8.1. It is included in the DB2e SDK available on the DB2 Everyplace Web site. In the SDK, an article called Generating DB2 Everyplace JSP applications using WebSphere Studio provides step-by-step instructions on how to develop and run a JSP application.

Question: Is it possible to store data in DB2e on a PDA while working with "offline" portlets? If so, is the data then automatically synchronized when the connection is restored?

Answer: Yes, you can work offline with DB2e on a PDA. We support the synchronization API so that an application can check on the connection and perform the synchronization.

Question: Does DB2e support synchronization using a wireless network connection?

Answer: For wireless support, DB2e uses WBXML (Wireless Application Protocol Binary XML), a compact binary representation of XML, to encode transmitted XML data, which reduces the number of total bytes transmitted across the network. In addition, the synchronization can start, stop at any point, and resume from that point, in case the device's connectivity strength to the network is low, the device's connectivity becomes out of range of the network, or the network is busy.

Question: DB2e makes enterprise information accessible to mobile devices from any location. This creates opportunities, but also poses new security threats. How does DB2e address these security concerns?

Answer: To protect data sent between mobile devices and the DB2e SyncServer, administrators can choose to encrypt the data during the transmission. When running as part of WebSphere Everyplace, you configure the server to use HTTPS.

Because mobile devices are often not kept in a secure location, and hence more prone to being stolen or lost, you must protect any sensitive corporate data residing on these devices. The administrator can specify, as part of the subscription policy, that data from sensitive tables be automatically encrypted before saving onto mobile devices. The encryption policy applies to all users synchronizing the subscription. Furthermore, the administrator can limit the allowed operations (delete, update, or insert) and specify, for example, that a table is for download read-only, or that users are not allowed to delete records.

Question: With changes being made at the server and at mobile devices, conflicts can occur. Does the DB2e Sync Server allow application specific actions to be taken when that happens?

Answer: We are looking for beta customers to try our new function, where the operation of the server is augmented with business logic supplied by customers during synchronization. For example, customers can implement a column based merge when conflicts occur. If you are interested to be a beta customer, please contact nakamura@us.ibm.com.

Question: What is DB2e Express Edition?

Answer: IBM is introducing DB2 Everyplace Express Edition to help mid-sized companies deploy mobile technology faster and more easily. DB2e Express offers mid-sized customers the same features of DB2e with a flexible price point of $379 per server (up to two processors) and $79 per user. DB2e Express is a new offering introduced with DB2e V8.1.4.

Question: Does DB2e support i-Series?

Answer: Yes, DB2e V8.1.4 has expanded the platform support to include i-Linux. Now customers and business partners can synchronize data and applications on the i-Series platform, allowing them to expand their current applications to mobile devices.

Question: Does DB2e support .NET environment?

Answer: Yes. In V8.1.4, DB2e features new .NET Framework and .Net Compact Framework interfaces to simplify mobile application development on Windows and PocketPC. We support ADO.NET Data Provider, Sync API, and Visual Studio .NET Plug-in for DB2 Everyplace.

Question: My company has DB2 and Oracle databases. Does DB2e support synchronization of Oracle database to devices?

Answer: Yes, DB2e supports synchronization for the DB2 Family, Oracle, MS SQL Server, Sybase®, and the Lotus Domino database.

Question: What are DB2e's competitive advantages?

Answer: DB2e is used by all our major ISVs, business partners, and customers. Customer reasons for choosing DB2e: fast data access, small footprint, ubiquitous (runs on everywhere), secure, incremental 2-way synchronization, and much more. For more details, see our customer testimonials page.

Related information

• DB2 Everyplace
• developerWorks DB2
• A JavaServer Pages Enterprise Resource Planning solution with DB2 Everyplace
• Training modules: DB2 Everyplace V8.1

About Meet the Experts

Meet the Experts is a monthly feature on WSDD. We give you access to the best minds in IBM WebSphere, product experts and executives who are waiting to answer your questions. You submit the questions, and we post the answers to the most popular questions.

About the author

Josephine Cheng is an IBM Fellow and manager of the IBM Database Technology Institute in the Silicon Valley Lab, San Jose, California, and has been at the forefront of relational database technology for more than 20 years.

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